diff --git a/Dockerfile--alpine.tmpl b/Dockerfile--alpine.tmpl
index f78af01..43190d2 100644
--- a/Dockerfile--alpine.tmpl
+++ b/Dockerfile--alpine.tmpl
@@ -3,35 +3,34 @@ ARG PYTHON_VERSION=3.12
 # --------------------------------------------- base1
 FROM python:${PYTHON_VERSION}-alpine AS base1
 
-RUN apk add --no-cache coreutils
+RUN apk add --no-cache \
+    coreutils \
+    bash \
+    mc \
+    procps \
+    openssh \
+    sshpass \
+    sudo \
+    git
 
 # --------------------------------------------- base2
 FROM base1 AS base2
 
-RUN apk add python3-dev build-base musl-dev linux-headers
-RUN apk add git 
+RUN apk add --no-cache \
+    python3-dev \
+    build-base\
+    musl-dev \
+    linux-headers
 
 # --------------------------------------------- final
 FROM base2 AS final
 
-RUN apk add mc
-RUN apk add bash
-
-# Full version of "ps" command
-RUN apk add --no-cache procps
-
-RUN apk add --no-cache openssh
-RUN apk add --no-cache sudo
-
-RUN adduser -D test
-
-RUN addgroup -S sudo
-RUN adduser test sudo
+RUN adduser -D test && addgroup -S sudo && adduser test sudo
 
 EXPOSE 22
 RUN ssh-keygen -A
 
-ADD --chown=test:test . /home/test/testgres
+COPY --chown=test:test . /home/test/testgres
 WORKDIR /home/test/testgres
 
 # It allows to use sudo without password
diff --git a/Dockerfile--altlinux_10.tmpl b/Dockerfile--altlinux_10.tmpl
index 2359459..4c96398 100644
--- a/Dockerfile--altlinux_10.tmpl
+++ b/Dockerfile--altlinux_10.tmpl
@@ -3,52 +3,56 @@ ARG PYTHON_VERSION=3
 # --------------------------------------------- base1
 FROM alt:p10 AS base1
 
-RUN apt-get update
-RUN apt-get install -y sudo curl ca-certificates
-RUN apt-get update
-RUN apt-get install -y openssh-server openssh-clients
-RUN apt-get install -y time
-
-# RUN apt-get install -y mc
-
-EXPOSE 22
-
-RUN ssh-keygen -A
-
-# --------------------------------------------- dev_tools
-FROM base1 AS base1_with_dev_tools
-
-RUN apt-get update
-RUN apt-get install -y git
+RUN apt-get update && apt-get install -y \
+    sudo \
+    curl \
+    ca-certificates \
+    openssh-server \
+    openssh-clients \
+    sshpass \
+    time \
+    su \
+    git \
+    && apt-get clean
 
 # --------------------------------------------- base2_with_python-3
-FROM base1_with_dev_tools AS base2_with_python-3
-RUN apt-get install -y python3
-RUN apt-get install -y python3-dev
+FROM base1 AS base2_with_python-3
+
+RUN apt-get update && apt-get install -y \
+    python3 \
+    python3-dev \
+    && apt-get clean
 
 ENV PYTHON_VERSION=3
 
 # --------------------------------------------- final
 FROM base2_with_python-${PYTHON_VERSION} AS final
 
+EXPOSE 22
+RUN ssh-keygen -A
+
 RUN adduser test -G wheel
 
 # It enables execution of "sudo service ssh start" without password
 RUN echo "test ALL=(ALL:ALL) NOPASSWD: ALL" >> /etc/sudoers
 
-ADD --chown=test:test . /home/test/testgres
+#
+# Altlinux 10 and 11 too slowly create a new SSH connection (x6).
+#
+# AI: SPEED UP SSH 6 TIMES (REMOVE REVERSE DNS LOOKUP TIMEOUTS)
+#
+RUN echo "UseDNS no" >> /etc/openssh/sshd_config
+
+COPY --chown=test:test . /home/test/testgres
 WORKDIR /home/test/testgres
 
 ENV LANG=C.UTF-8
 
-USER test
+RUN chmod 700 /home/test/ && \
+    mkdir -p /home/test/.ssh && \
+    chown -R test:test /home/test/.ssh
 
-RUN chmod 700 ~/
-RUN mkdir -p ~/.ssh
-
-#
-# Altlinux 10 and 11 too slowly create a new SSH connection (x6).
-#
+USER test
 
 ENTRYPOINT sh -c " \
 set -eux; \
diff --git a/Dockerfile--altlinux_11.tmpl b/Dockerfile--altlinux_11.tmpl
index 8f0f426..198414b 100644
--- a/Dockerfile--altlinux_11.tmpl
+++ b/Dockerfile--altlinux_11.tmpl
@@ -3,55 +3,57 @@ ARG PYTHON_VERSION=3
 # --------------------------------------------- base1
 FROM alt:p11 AS base1
 
-RUN apt-get update
-RUN apt-get install -y sudo curl ca-certificates
-RUN apt-get update
-RUN apt-get install -y openssh-server openssh-clients
-RUN apt-get install -y time
-
-# pgrep (for testgres.os_ops)
-RUN apt-get install -y procps
-
-# RUN apt-get install -y mc
-
-EXPOSE 22
-
-RUN ssh-keygen -A
-
-# --------------------------------------------- dev_tools
-FROM base1 AS base1_with_dev_tools
-
-RUN apt-get update
-RUN apt-get install -y git
+RUN apt-get update && apt-get install -y \
+    sudo \
+    curl \
+    ca-certificates \
+    openssh-server \
+    openssh-clients \
+    sshpass \
+    time \
+    su \
+    git \
+    procps \
+    && apt-get clean
 
 # --------------------------------------------- base2_with_python-3
-FROM base1_with_dev_tools AS base2_with_python-3
-RUN apt-get install -y python3
-RUN apt-get install -y python3-dev
+FROM base1 AS base2_with_python-3
+
+RUN apt-get update && apt-get install -y \
+    python3 \
+    python3-dev \
+    && apt-get clean
 
 ENV PYTHON_VERSION=3
 
 # --------------------------------------------- final
 FROM base2_with_python-${PYTHON_VERSION} AS final
 
+EXPOSE 22
+RUN ssh-keygen -A
+
 RUN adduser test -G wheel
 
 # It enables execution of "sudo service ssh start" without password
 RUN echo "test ALL=(ALL:ALL) NOPASSWD: ALL" >> /etc/sudoers
 
-ADD --chown=test:test . /home/test/testgres
+#
+# Altlinux 10 and 11 too slowly create a new SSH connection (x6).
+#
+# AI: SPEED UP SSH 6 TIMES (REMOVE REVERSE DNS LOOKUP TIMEOUTS)
+#
+RUN echo "UseDNS no" >> /etc/openssh/sshd_config
+
+COPY --chown=test:test . /home/test/testgres
 WORKDIR /home/test/testgres
 
 ENV LANG=C.UTF-8
 
-USER test
+RUN chmod 700 /home/test/ && \
+    mkdir -p /home/test/.ssh && \
+    chown -R test:test /home/test/.ssh
 
-RUN chmod 700 ~/
-RUN mkdir -p ~/.ssh
-
-#
-# Altlinux 10 and 11 too slowly create a new SSH connection (x6).
-#
+USER test
 
 ENTRYPOINT sh -c " \
 set -eux; \
diff --git a/Dockerfile--astralinux_1_7.tmpl b/Dockerfile--astralinux_1_7.tmpl
index b68b2fa..f696c44 100644
--- a/Dockerfile--astralinux_1_7.tmpl
+++ b/Dockerfile--astralinux_1_7.tmpl
@@ -3,28 +3,33 @@ ARG PYTHON_VERSION=3
 # --------------------------------------------- base1
 FROM packpack/packpack:astra-1.7 AS base1
 
-RUN apt update
-RUN apt install -y sudo curl ca-certificates
-RUN apt update
-RUN apt install -y openssh-server
-# RUN apt install -y time
-# RUN apt install -y netcat-traditional
-
-RUN apt install -y git
-
-# RUN apt install -y mc
-# RUN apt install -y nano
+ENV DEBIAN_FRONTEND=noninteractive
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    sudo \
+    curl \
+    ca-certificates \
+    openssh-server \
+    sshpass \
+    iproute2 \
+    git \
+    && rm -rf /var/lib/apt/lists/*
 
 # --------------------------------------------- base2_with_python-3
 FROM base1 AS base2_with_python-3
-RUN apt install -y python3 python3-dev python3-venv
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    python3 \
+    python3-dev \
+    python3-venv \
+    && rm -rf /var/lib/apt/lists/*
+
 ENV PYTHON_VERSION=3
 
 # --------------------------------------------- final
 FROM base2_with_python-${PYTHON_VERSION} AS final
 
 EXPOSE 22
-
 RUN ssh-keygen -A
 
 RUN useradd -m test
@@ -36,10 +41,10 @@ RUN useradd -m test
 RUN echo "test ALL=(ALL:ALL) NOPASSWD:ALL" >> /etc/sudoers
 
 # THIS CMD IS NEEDED TO CONNECT THROUGH SSH WITHOUT PASSWORD
-RUN sh -c "echo "test:*" | chpasswd -e"
-RUN sed -i 's/UsePAM yes/UsePAM no/' /etc/ssh/sshd_config
+RUN echo "test:*" | chpasswd -e && \
+    sed -i 's/UsePAM yes/UsePAM no/' /etc/ssh/sshd_config
 
-ADD --chown=test:test . /home/test/testgres
+COPY --chown=test:test . /home/test/testgres
 WORKDIR /home/test/testgres
 
 ENV LANG=C.UTF-8
diff --git a/Dockerfile--ubuntu_24_04.tmpl b/Dockerfile--ubuntu_24_04.tmpl
index d953a52..6cecb10 100644
--- a/Dockerfile--ubuntu_24_04.tmpl
+++ b/Dockerfile--ubuntu_24_04.tmpl
@@ -3,27 +3,36 @@ ARG PYTHON_VERSION=3
 # --------------------------------------------- base1
 FROM ubuntu:24.04 AS base1
 
-RUN apt update
-RUN apt install -y sudo curl ca-certificates
-RUN apt update
-RUN apt install -y openssh-server
-RUN apt install -y time
-RUN apt install -y netcat-traditional
+# Disable interactive apt questions so that the build doesn't hang when setting time zones
+ENV DEBIAN_FRONTEND=noninteractive
 
-RUN apt install -y git
-
-# RUN apt install -y mc
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    sudo \
+    curl \
+    ca-certificates \
+    openssh-server \
+    sshpass \
+    time \
+    netcat-traditional \
+    iproute2 \
+    git \
+    && rm -rf /var/lib/apt/lists/*
 
 # --------------------------------------------- base2_with_python-3
 FROM base1 AS base2_with_python-3
-RUN apt install -y python3 python3-dev python3-venv
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    python3 \
+    python3-dev \
+    python3-venv \
+    && rm -rf /var/lib/apt/lists/*
+
 ENV PYTHON_VERSION=3
 
 # --------------------------------------------- final
 FROM base2_with_python-${PYTHON_VERSION} AS final
 
 EXPOSE 22
-
 RUN ssh-keygen -A
 
 RUN useradd -m test
@@ -31,7 +40,7 @@ RUN useradd -m test
 # It enables execution of "sudo service ssh start" without password
 RUN echo "test ALL=(ALL:ALL) NOPASSWD:ALL" >> /etc/sudoers
 
-ADD --chown=test:test . /home/test/testgres
+COPY --chown=test:test . /home/test/testgres
 WORKDIR /home/test/testgres
 
 ENV LANG=C.UTF-8